discussion/index.ndjson

@@ -10,7 +10,7 @@
 {"type":"discussion","id":"DSC-0057","status":"open","ticket":"multi-frontend-frontend-backend-contract","title":"Estabilizar contrato entre frontend e backend comum","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","compiler-pbs","ir","backend","multi-frontend"],"agendas":[{"id":"AGD-0060","file":"AGD-0060-multi-frontend-frontend-backend-contract.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
 {"type":"discussion","id":"DSC-0056","status":"open","ticket":"multi-frontend-remove-pbs-branches","title":"Remover verificacoes explicitas de PBS do codigo comum","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","compiler-pbs","studio","frontend","coupling","multi-frontend"],"agendas":[{"id":"AGD-0059","file":"AGD-0059-multi-frontend-remove-pbs-branches.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
 {"type":"discussion","id":"DSC-0055","status":"open","ticket":"multi-frontend-compiler-vs-language-services","title":"Separar compilacao de servicos editoriais de frontend","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","studio","lsp","editor","frontend","multi-frontend"],"agendas":[{"id":"AGD-0058","file":"AGD-0058-multi-frontend-compiler-vs-language-services.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
-{"type":"discussion","id":"DSC-0054","status":"in_progress","ticket":"multi-frontend-provider-contract","title":"Introduzir provider completo de frontend","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","studio","frontend","registry","multi-frontend"],"agendas":[{"id":"AGD-0057","file":"AGD-0057-multi-frontend-provider-contract.md","status":"accepted","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[{"id":"DEC-0040","file":"DEC-0040-frontendprovider-explicito-como-contrato-de-frontend.md","status":"accepted","created_at":"2026-07-15","updated_at":"2026-07-15","ref_agenda":"AGD-0057"}],"plans":[{"id":"PLN-0103","file":"PLN-0103-specify-frontend-provider-and-registry-contract.md","status":"done","created_at":"2026-07-15","updated_at":"2026-07-15","ref_decisions":["DEC-0040"]},{"id":"PLN-0104","file":"PLN-0104-introduce-frontendprovider-registry-api.md","status":"done","created_at":"2026-07-15","updated_at":"2026-07-15","ref_decisions":["DEC-0040"]},{"id":"PLN-0105","file":"PLN-0105-wrap-pbs-frontend-as-explicit-provider.md","status":"done","created_at":"2026-07-15","updated_at":"2026-07-15","ref_decisions":["DEC-0040"]},{"id":"PLN-0106","file":"PLN-0106-migrate-common-consumers-to-provider-lookup.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15","ref_decisions":["DEC-0040"]}],"lessons":[]}
+{"type":"discussion","id":"DSC-0054","status":"in_progress","ticket":"multi-frontend-provider-contract","title":"Introduzir provider completo de frontend","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["compiler","compiler-general","studio","frontend","registry","multi-frontend"],"agendas":[{"id":"AGD-0057","file":"AGD-0057-multi-frontend-provider-contract.md","status":"accepted","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[{"id":"DEC-0040","file":"DEC-0040-frontendprovider-explicito-como-contrato-de-frontend.md","status":"accepted","created_at":"2026-07-15","updated_at":"2026-07-15","ref_agenda":"AGD-0057"}],"plans":[{"id":"PLN-0103","file":"PLN-0103-specify-frontend-provider-and-registry-contract.md","status":"done","created_at":"2026-07-15","updated_at":"2026-07-15","ref_decisions":["DEC-0040"]},{"id":"PLN-0104","file":"PLN-0104-introduce-frontendprovider-registry-api.md","status":"done","created_at":"2026-07-15","updated_at":"2026-07-15","ref_decisions":["DEC-0040"]},{"id":"PLN-0105","file":"PLN-0105-wrap-pbs-frontend-as-explicit-provider.md","status":"done","created_at":"2026-07-15","updated_at":"2026-07-15","ref_decisions":["DEC-0040"]},{"id":"PLN-0106","file":"PLN-0106-migrate-common-consumers-to-provider-lookup.md","status":"done","created_at":"2026-07-15","updated_at":"2026-07-15","ref_decisions":["DEC-0040"]}],"lessons":[]}
 {"type":"discussion","id":"DSC-0053","status":"open","ticket":"pbs-lsp-call-and-type-hierarchy","title":"PBS LSP Call and Type Hierarchy","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["studio","lsp","vscode","compiler-pbs","editor","call-hierarchy","type-hierarchy"],"agendas":[{"id":"AGD-0056","file":"AGD-0056-pbs-lsp-call-and-type-hierarchy.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
 {"type":"discussion","id":"DSC-0052","status":"open","ticket":"pbs-lsp-document-links","title":"PBS LSP Document Links","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["studio","lsp","vscode","compiler-pbs","editor","document-links","imports"],"agendas":[{"id":"AGD-0055","file":"AGD-0055-pbs-lsp-document-links.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}
 {"type":"discussion","id":"DSC-0051","status":"open","ticket":"pbs-lsp-diagnostics-ux","title":"PBS LSP Diagnostics UX","created_at":"2026-07-15","updated_at":"2026-07-15","tags":["studio","lsp","vscode","compiler-pbs","editor","diagnostics","ux"],"agendas":[{"id":"AGD-0054","file":"AGD-0054-pbs-lsp-diagnostics-ux.md","status":"open","created_at":"2026-07-15","updated_at":"2026-07-15"}],"decisions":[],"plans":[],"lessons":[]}

discussion/workflow/plans/PLN-0106-migrate-common-consumers-to-provider-lookup.md

@@ -2,7 +2,7 @@
 id: PLN-0106
 ticket: multi-frontend-provider-contract
 title: Migrate common consumers to provider lookup
-status: open
+status: done
 created: 2026-07-15
 ref_decisions: [DEC-0040]
 tags: [compiler, compiler-general, studio, frontend, registry, multi-frontend]

prometeu-compiler/prometeu-build-pipeline/src/main/java/p/studio/compiler/workspaces/stages/FrontendPhasePipelineStage.java

@@ -17,13 +17,7 @@ public class FrontendPhasePipelineStage implements PipelineStage {
     @Override
     public BuildingIssueSink run(final BuilderPipelineContext ctx, final LogAggregator logs) {
         final var frontedSpec = ctx.resolvedWorkspace.frontendSpec();
-        final var service = FrontendRegistryService.getFrontendPhaseService(frontedSpec.getLanguageId());
+        final var provider = FrontendRegistryService.require(frontedSpec.getLanguageId());
-        if (service.isEmpty()) {
-            return BuildingIssueSink.empty()
-                    .report(builder -> builder
-                            .error(true)
-                            .message("[BUILD]: unable to find a service for frontend phase: " + frontedSpec.getLanguageId()));
-        }
         final var projectTable = ctx.resolvedWorkspace.graph().projectTable();
         final var fileTable = ctx.fileTable;
         final var frontendPhaseContext = new FrontendPhaseContext(
@@ -36,7 +30,7 @@ public class FrontendPhasePipelineStage implements PipelineStage {
                 assetSurfaceContextLoader.load(ctx.resolvedWorkspace.mainProject().getRootPath()));
         final var diagnostics = DiagnosticSink.empty();
         final var issues = BuildingIssueSink.empty();
-        ctx.irBackend = service.get().compile(frontendPhaseContext, diagnostics, logs, issues);
+        ctx.irBackend = provider.compiler().compile(frontendPhaseContext, diagnostics, logs, issues);
         logs.using(log).debug("Frontend phase completed successfully!");
         adaptDiagnostics(diagnostics, issues);
         return issues;

prometeu-compiler/prometeu-build-pipeline/src/test/java/p/studio/compiler/specs/FrontendProviderBoundaryTest.java

@@ -0,0 +1,59 @@
+package p.studio.compiler.specs;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.fail;
+
+class FrontendProviderBoundaryTest {
+
+    @Test
+    void commonModulesMustNotInstantiatePbsFrontendPhaseServiceDirectly() throws IOException {
+        final var repoRoot = findRepoRoot(Path.of("").toAbsolutePath().normalize());
+        final var commonSourceRoots = List.of(
+                repoRoot.resolve("prometeu-compiler/prometeu-build-pipeline/src/main/java"),
+                repoRoot.resolve("prometeu-compiler/prometeu-deps/src/main/java"),
+                repoRoot.resolve("prometeu-studio/src/main/java"),
+                repoRoot.resolve("prometeu-app/src/main/java"));
+
+        for (final var sourceRoot : commonSourceRoots) {
+            if (!Files.exists(sourceRoot)) {
+                continue;
+            }
+
+            try (final var files = Files.walk(sourceRoot)) {
+                final var violations = files
+                        .filter(path -> path.toString().endsWith(".java"))
+                        .filter(path -> contains(path, "new PBSFrontendPhaseService("))
+                        .toList();
+                if (!violations.isEmpty()) {
+                    fail("common modules must resolve frontend compiler behavior through FrontendProvider: " + violations);
+                }
+            }
+        }
+    }
+
+    private boolean contains(final Path path, final String needle) {
+        try {
+            return Files.readString(path).contains(needle);
+        } catch (IOException e) {
+            throw new IllegalStateException("failed to read " + path, e);
+        }
+    }
+
+    private Path findRepoRoot(final Path start) {
+        var current = start;
+        while (current != null) {
+            if (Files.exists(current.resolve("settings.gradle.kts"))) {
+                return current;
+            }
+            current = current.getParent();
+        }
+        fail("unable to locate repository root from " + start);
+        return start;
+    }
+}

prometeu-compiler/prometeu-deps/src/main/java/p/studio/compiler/utilities/PrometeuManifestUtils.java

@@ -60,7 +60,7 @@ public final class PrometeuManifestUtils {
                     .message("[DEPS]: invalid 'target' \"" + dto.target() + "\": " + manifestPathCanon));
         }
         final var language = StringUtils.isBlank(dto.language())
-                ? FrontendRegistryService.getDefaultFrontendSpec().getLanguageId()
+                ? FrontendRegistryService.getDefaultProvider().specification().getLanguageId()
                 : dto.language();
         final var dependencies = DependencyResolver.resolveDependencies(mainProjectRootPathCanon, dto.dependencies(), issuesLocal);
         if (ReadOnlyCollection.isNotEmpty(issuesLocal)) {

prometeu-compiler/prometeu-deps/src/main/java/p/studio/compiler/workspaces/phases/DiscoverPhase.java

@@ -55,23 +55,24 @@ public class DiscoverPhase implements DependencyPhase {
             ctx.rootStdlib = manifest.get().stdlib();
             ctx.target = manifest.get().target();
         }
-        final var frontendSpec = FrontendRegistryService.getFrontendSpec(manifest.get().language());
+        final var frontendProvider = FrontendRegistryService.getProvider(manifest.get().language());
         // Returns empty when language is unknown
-        if (frontendSpec.isEmpty()) {
+        if (frontendProvider.isEmpty()) {
             issues.report(builder -> builder
                     .error(true)
                     .message("[DEPS]: unknown language " + manifest.get().language() + " for project " + manifest.get().name()));
             return Optional.empty();
         }
+        final var frontendSpec = frontendProvider.get().specification();
         // Enforces consistent language across projects
         if (Objects.isNull(ctx.frontendSpec)) {
-            ctx.frontendSpec = frontendSpec.get();
+            ctx.frontendSpec = frontendSpec;
-        } else if (!ctx.frontendSpec.getLanguageId().equals(frontendSpec.get().getLanguageId())) {
+        } else if (!ctx.frontendSpec.getLanguageId().equals(frontendSpec.getLanguageId())) {
             // Reports language inconsistency across projects
             issues.report(builder -> builder
                     .error(true)
                     .message(String.format("[DEPS]: inconsistent language: [ %s ] has \"%s\" but should be \"%s\"",
-                            manifest.get().name(), frontendSpec.get().getLanguageId(), ctx.frontendSpec.getLanguageId())));
+                            manifest.get().name(), frontendSpec.getLanguageId(), ctx.frontendSpec.getLanguageId())));
             return Optional.empty();
         }
         final var projectInfo = ProjectInfo

prometeu-compiler/prometeu-frontend-registry/build.gradle.kts

@@ -6,7 +6,7 @@ dependencies {
     implementation(project(":prometeu-infra"))
     implementation(project(":prometeu-compiler:prometeu-compiler-core"))
 
-    implementation(project(":prometeu-compiler:prometeu-frontend-api"))
+    api(project(":prometeu-compiler:prometeu-frontend-api"))
 
     implementation(project(":prometeu-compiler:frontends:prometeu-frontend-pbs"))
-}
+}

prometeu-compiler/prometeu-frontend-registry/src/main/java/p/studio/compiler/FrontendRegistryService.java

@@ -21,7 +21,11 @@ public class FrontendRegistryService {
     }
 
     public static FrontendSpec getDefaultFrontendSpec() {
-        return require(PBSDefinitions.PBS.getLanguageId()).specification();
+        return getDefaultProvider().specification();
+    }
+
+    public static FrontendProvider getDefaultProvider() {
+        return require(PBSDefinitions.PBS.getLanguageId());
     }
 
     public static Optional<FrontendSpec> getFrontendSpec(final String languageId) {

prometeu-compiler/prometeu-frontend-registry/src/test/java/p/studio/compiler/FrontendRegistryServiceTest.java

@@ -33,4 +33,12 @@ class FrontendRegistryServiceTest {
         assertEquals(1, specs.size());
         assertEquals(PBSDefinitions.PBS.getLanguageId(), specs.getFirst().getLanguageId());
     }
+
+    @Test
+    void providerListingShouldExposeOnlyPbsByDefault() {
+        final var providers = FrontendRegistryService.listProviders();
+
+        assertEquals(1, providers.size());
+        assertEquals(PBSDefinitions.PBS.getLanguageId(), providers.getFirst().specification().getLanguageId());
+    }
 }

prometeu-studio/src/main/java/p/studio/projects/ProjectLanguageCatalogService.java

@@ -9,8 +9,8 @@ import java.util.Objects;
 
 public final class ProjectLanguageCatalogService {
     public List<ProjectLanguageTemplate> listLanguageTemplates() {
-        return FrontendRegistryService.listFrontendSpecs().stream()
+        return FrontendRegistryService.listProviders().stream()
-                .map(this::toTemplate)
+                .map(provider -> toTemplate(provider.specification()))
                 .sorted(Comparator.comparing(ProjectLanguageTemplate::languageId, String.CASE_INSENSITIVE_ORDER))
                 .toList();
     }

prometeu-studio/src/test/java/p/studio/projects/ProjectLanguageCatalogServiceTest.java

@@ -0,0 +1,18 @@
+package p.studio.projects;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ProjectLanguageCatalogServiceTest {
+
+    @Test
+    void shouldListLanguagesFromRegisteredProviders() {
+        final var service = new ProjectLanguageCatalogService();
+
+        final var templates = service.listLanguageTemplates();
+
+        assertEquals(1, templates.size());
+        assertEquals("pbs", templates.getFirst().languageId());
+    }
+}